Exemplary embodiments pertain to the art of electromagnetic actuators, and more particularly, to reciprocating electromagnetic actuators with a flux-balanced armature and stationary cores.
Electromagnetic linear actuators convert electrical energy into mechanical energy expressed as translatory motion. Electromagnetic actuators can be classified as electric motor driven actuators, solenoid actuators, and moving coil actuators. Reciprocating motion is a repetitive up-and-down or back-and-forth linear motion. Electromagnetic linear actuators are found in a wide range of mechanisms including reciprocating valves, engines and pumps. Reciprocating linear actuators that reciprocate an armature with permanent magnets (PMs) may not maximize force density (force per mass or per volume). PM actuators can be cost prohibitive for some applications and can experience higher rates of malfunction. For example, the operating temperature of PM devices may be limited and can be dependent on the grade of the PM material. Furthermore, PM devices can become demagnetized with time due to repetitive impact stationary armature-stationary core.
In other aspects, the armature shape may also provide limitations. For example, armatures of some actuators with a uniform or flat surface may not provide adequate magnetic flux control that provide actuation forces needed for some applications.